Color cast on UV printed products is a common issue in production. It is not merely caused by ink quality, but affected by a combination of software & hardware, consumables, environment and parameters. The main factors are listed below:

1. Color management and file settings

Wrong color mode of source files is a frequent cause. Designs created in RGB and printed directly will show color difference, because the printer mixes colors based on CMYK (plus white ink) and their gamuts differ. Mismatched ICC profiles, missing color calibration or abnormal adjustment of image level and saturation also lead to color cast.

2. Ink-related factors

Different ink batches, mixed use of ink from different brands or models bring inconsistent pigment formulas and color performance. Aged and precipitated ink, low ink level, air in tubes or unstable ink supply cause uneven ink output and color shift. Improper white ink ratio will cover the base material and interfere with color rendering.

3. Printhead and ink supply failures

Partial nozzle clogging, deflection and uneven ink drop ejection reduce the output of a certain color and result in color cast. Incorrect printhead height or abnormal negative pressure changes ink droplet size and position, causing color deviation. Aged tubes and blocked filters also hurt ink supply stability.

4. Substrate materials

Materials have different base colors and ink absorption features. White acrylic, wood, glass and dark panels produce different visual results even with identical print settings. Dust, oil stains or uneven coating on substrates alter the final color after UV curing.

5. UV curing lamp

Aging UV lamps, low power, incorrect lamp distance lead to inconsistent curing. Under-curing causes faint color and cast; over-curing tends to yellow the print. Excessive curing temperature may discolor the ink.

6. Printer parameters

Improper settings of print passes, ink limit, feathering and step value; misalignment in bidirectional printing creates ghosting and color mixing, which looks like color cast. Wrong print resolution also affects color reproduction.

7. Working environment

Fluctuating temperature and humidity change ink viscosity and droplet status. Different ambient lighting changes human visual perception and may cause false judgment of color deviation.

To reduce color cast, standardize your color workflow, stick to the same ink brand and batch, maintain printheads and ink paths regularly, make separate ICC calibration for each substrate, and control UV lamp status and workshop conditions.